A WiFi “hotspot” provides a wireless access point by which users may access a wireless LAN (WLAN) for data communications, VoIP calls, and like services. As WiFi “hotspots” become more common, and more users being using WiFi “hotspots” to place VoIP calls, call admission control is becoming quite important in order to ensure that WiFi “hotspots” do not become overloaded. The application of call admission control on a pervasive WLAN is more complicated than simply prioritizing real-time traffic over non-real-time traffic or allowing a predetermined number of calls. WLAN traffic is non-deterministic and, further, channel access is based on a binary back-off algorithm and is, by nature, variable, based on the number of clients accessing the network.
Disadvantageously, existing call admission control schemes in WLANs do not work well. For example, placement of a static limit on the number of wireless user terminals that can access a WiFi “hotspot” results in an inefficient use of the resources available at the WiFi “hotspot”. Furthermore, requiring the wireless user terminals to register with the WiFi “hotspots” is expensive, both in terms of the additional complexity of the wireless user terminal (i.e., to enable the wireless user terminal to determine what resources is may require for a call in the future) and in terms of resources wasted at the WiFi hotspot (i.e., since the WiFi “hotspot” must reserve bandwidth for each wireless user terminal, regardless of whether or not the wireless user terminal will ever use the reserved bandwidth).